Apparatus for pre-amputation freezing



H. c. w. SCHNEPF ETAL APPARATUS FOR PRE-AMPUTATION FREEZING Filed Dec.422, 1952 March 4, i958 United States Patent APPARATUS FOR PRE-AMPUTATINFREEZNG Herman C. W. Schnepf and Robert C. Webber, indianapolis, ind.;said Schnepf assigner to said Webber Application December 22, 1952,Serial No. 327,342

1 Claim. (Cl. 12S-402) The present invention relates to a method andapparatus foi freezing an extremity of a patients limb preliminary toamputation of the limb; and the invention is particularly concerned withthe provision of method and apparatus details whereby improved controlover the condition of the limb extremity' can be achieved while the riskof deleterious effects upon the patient is substantially reduced andanalgesia is much more quickly and effectively established.

The primary object of the invention, then, is to provide a method andapparatus whereby a limb extremity may have its temperature reduced,quite quickly, to a Value such as to halt the flow of body uids withinthe extremity, by exposure to a completely circumambient atmosphere ofextremely low temperature. A further object of the invention is toprovide a method and apparatus whereby, after the quick establishment ofoptimum temperature throughout the extremity under treatment, ythetemperature of such circumambient atmosphere may be changed in such afashion that the extremity will beheld at opti-mum temperatures forwhatever period may be desirable, and with minimum discomfort to thepatient and minimum attention on the part of the nursing stat. A furtherobject of the invention is to provide means whereby the above optimumconditions may be achieved and maintained through exposure of theextremity to a dry atmosphere of desired temperatures.

A still further object of the invention is to provide specificapparatus, including a chamber in which the extremity under treatmentmay be received, means for maintaining any desired temperatureconditions within such chamber, and barrier means,.so constructed as toaccommodate itself to the patients limb in the region imme-Y diatelyproximal to the extremity under treatment, such barrier means beingcapable -of substantially preventing heat exchange and/or air flowbetween the atmosphere within said chamber, to which the extremity isexposed, D

and the atmosphere without said chamber, to which the remainder of thepatients limb is exposed.

Further objects of the invention will appear as the descriptionproceeds. l Y v To the accomplishment :of the above and related objects,our invention may be embodied in the form i1- lustrated in theaccompanying drawings, vattention being called to the fact, however,that the drawings are illustrative only, and that change maybe made inthe specific construction illustrated and described and in the specificsteps stated, so long as thescope of the appended claims is notviolated.

Fig. l is a perspective View of one form of apparatus embodying ourinvention and adaptable for use in the practice of our process;

Fig. 2 is a central vertical section through the freezer cabinet;

Fig. 3 is Va ragmental section taken substantially on the line 3, 3 OfFg- `2; and

Eig, ,4 is a diagrammatic illustration of the lrefrigeraties 'mechanismabsents@ with 'the freezer' sab-iam# Y, 2,825,338 Patented Max'- 4,19.5.8

f. ice

In the case of individuals suffering from diabetes mellitus,arteriosclerosis, obliterative arterial diseases and the like, andsometimes in the case of vasopastic conditions, a minor injury to a toeor any other portion of a foot, and sometimes to a hand, will frequentlyresult in the development of spontaneous .gangrene When such a conditionarises,` it isalmost invariably found that it is necessary to amputatethe limb, preferably just below `the knee, .leaving two and one-halt tothree inches of tibia. The Ysite of amputation is, of course, dictatedprimarily by the fact that blood supply, `upon which spontaneous repairis dependent, is usually optimum here, and bythe fact that the best ofprosthetic devices are designed .for association with such a stump.

Almost invariably, when s uch a gangrenous condition develops., it isfound that the patients general condition is'such that.immediateamputation is contra-indicated. In diabetic patients, forinstance, gangrene usually will not thus develop unless the patient haslost stabilization; and in many instances, a period of four to ten dayswill elapse befloresatisfactory stabilization can be achieved. In theother abnormal conditions above mentioned, it is usually highlyimportant that the patient shall Ahave treatment to improve his generalcondition before he is subjected to the shock of arnlnitation.

Lfalzed treatment of the infected ,region by heating, poulticins and thelike, iS utterly indicative to inhibit the development and diffusion andabsorption of the noxious products of necrosis and to prevent anascendinglymphangitis, and is almost equally ineiective to provide.analgesic relief for the patient. It is deemed essential to halt thespread of infection, and it is highly desirable to provide a Ireasonabledegree ot comfort for the patient, during the ytreatment required toprepare the patient for surgery.

It is conventional, therefore, tochill the aiected extremity to a degreesuilicient to halt the flow of body fluids in the affected region; and,prior to our invention, the -only procedure used for that purposev hasinvolved the use of an ice-packed boot, with attendant seriousdisadvantages, well known to those versed in the att.

We have discovered that, through the use of proper refrigeratingapparatus, it is possible to eliminate lor alleviate all of theobjectionable features of the previouslyused procedure. Ian theaccompanying` drawings, wehave illustrated .one form of apparatus inwhich 'our invention may be embodied, and through which our novellmethod may be practiced. In those drawings,.the reference numeral lllindicates generally a cabinet formed to define a chamber 11 surrounded.on five sides by preferably plane walls and having, at its sixth side,an open entryway 117;. Evaporator coils i4 are suitably secured inheat-exchanging relationship to all ofthe walls 1,2.l The bottom oftheentryway is located somewhat above the floor 16 of the chamber 11 and isprovided with a pad 15, preferably of sponge rubber, upon which theregion `of a patients leg immediately proximal with respect to hisv footY18 `may be vreasonably comfortably supported atv a level such that thepatients heel is spaced above the chamber oor 116, as is clearlyillustrated jin Fig. 2;

Prcferably,'but not essentially, we provide` a barrier whichsubstantially closes the entryway 17. Inr the illustratedv embodiment ofthe apparatus of the present :invention, said barrier comprisesvagenerally Ll-shapedframe 19 whose b ase and legs are formed to dene acontinuous, inwardly-facing channel 20, and a suitably proportionedblock 21 of sponge rubber or the like has its top and side edges snuglyseated insaid channel. Preferably, but not necessarily, the lower lendslof the vflilme arms will be turned slightly inwardly to aid insupporting theY block 21 in place in the channel. Said block, of;course, spans the, area delined within the frame 12v-aad f -The conduit33 carries, latritsl Youter end, a s

hazardoluis."Y Y l;

A The switch 28, ofcourse, dominates-the VcicmtrolfniechanistnV 35,Ythearrangement being such that Yany desired temperatu'rewithin thechamber. 11 Vmay-beQattainedf'and Y maintained automatically,5 uponsuitable"adjustmeentV of' the ewitch 28. f The entire system maybeenergized,irornV Y Y a'co'nventio'nal lighting Circuit, through-SV a:plug 44' carried fr' at the*endof.n.exible'conductor.'f

the' parts are vso proportioned and designed that; when theV base-,ofsaid frame is hingedlysupported, as at 22,

' inside the chamber; 11, substantially. in

upon the cabinet above the entryway 17, the barrier will tendrto fall bygravity into closingrelation Withrtheenf Atitslower'edge,the block 21 issubstantially centr'ally Y pryidedjwith'a'slit 23 which opensthroug'hthe Yloweredge :oithe'block and'leadsinto a substantiallycircular 'i opening'24gl proportioned andrdesigned snugly to em-Ibrace"thejpatientsleg just aboverthe ankle, when the Y. 'partsfare inthe solid line positions ofFig.V 2. Y

I ."Thecabinet-'IOV comprises also :an outer, shell "25, the

region'betweenthe'walls V12 and the shell 25 vpreferably bengfpacked.with ia suitable insulating material such as, ,foriins'tance,Fiberglas; and-the shellv is suitably Welded or otherwise secured tothe vyallsV 12 so that the'insulati'ng material 26 is hermeticallyenclosed.V l

Preferably, Va Vthermometer V27., having'A a bulb disposed within the'chamber 11, is mounted on'an outer Wall of*Y the cabinet; and-a controlswitch 28, whose function will jappearrhereinafter', isrrr'iournted`adjacent the thermometer.

' Y .The cabinetas a Ywhole is 'so proportioned'anddesigned 'thatfit'maystand, inthe attitude suggested in Fig. 1, upon afhospital bed' orQup'ona ltable'suitably located adjacent 'thefbed,' andvat valevel such thatthe patients footl may beosuspendedwithin thev chamber 11,;in themannerY sug- -Y gestedgin Fig.' 2', .withi minimum discomfort. tothepatient.

" A"'separateV unit, indicated generally Vbyrthe Vreference numeral29,lcomprises a -frame .30V mountedV on casters.'

3I'and so`proportioned anddesigned that 'itmayfbe con-V viently disposedbeneath aconventional hospital bed. ,A f

vrefrigeration system', of Vany .desired form, lis indicated Ygenerallyby the reference numeral 32, and, kasV shown', will includeV anelectricmotor, a c'omlgyressor,y Valccmdenser, and conduits 33 and 34for establishing the usual refriger ation cycleow Vbetween the unit 32'andthe coilf14,one

conduitfbeing connected toene end of the coil 14 andtheV'o'the'r'conduitrbeing connected to theother endlofsaid coil.Y *InYwhat we -believe to bethe optimum `form offour Y apparatus",Vtheconduits 33 and l34 will Vl;\e'fleiiible,'rub

Vberoidrnater-ial.of suchrcharacter-as Yto sureswhich are inherent inthe system.

withstand the pres- Aconti'olunit of Aconventional formisindicatedrat-i35 and is connected by aeirible electricY conductor,36,t0; Ytheswitch 28, preferablysthrough a conventionahgseparable`Vconji'iect'or, indicated at 37.VY

Y. Y' 38 whilevt'he Vconduit `34Y -carriesa similar shutoi yalve39.SimilarA valves 40 and 41 are preferably supported upon thejoppositeVends:y of the coil 174,'to control the sameyand connector means 42 YandV43V areprovidedp betweenlthe Y. valves on the conduits andthe valves onthe'coiLfor coni. .f

ne'cting said conduits with the coil. Through this arrange- Vm'ent, ofVcourse, it is possible, withminimum diifnculty, to s' disconnectthe'cabinet- 10 from the .unit 29, throughrtlici Yseparable connectors37,42'and43.1Since;thecabinet V10Y `is, as above explained, aVhermetically tight.V structure,V

the` entire cabinet unit may;be immersed inY sterilizing liquid, placedyin a steam;cabinet, or "subjected 'to dry,Y

sterilizingtemperaturesjras highas 2 503 Fahrenheit, with# outthe lossof refrigerant and without hazard. We pre#Y vrently .believe'that thesystem-'shouldluse va Frecm?Y `re-lY man 'valve the position illustratedin Fig. 2. The patient andthe cabinet are mutually adjusted in positionuntil the patient'isreasonably comfortableg'and thereupon the barrier islowered to its solidline position of Fig. 2, the patients leg passingthrough the slit A23 and entering Vthe opening 24.Y p Y Y Now,'theunitr29 is placedin any suitable position suchY as, for instance, underthe patients'bemand Vthe plug'4'4 {found that analgesiaY usuallyarisesfwithin two andone'- e `half to `three'hours `and that ilow ofbody fluids :within Y 1 the iootrV is usually completelyhalted withinsubstantially.V f the same length of time; Y f Q .The barrier vprovidedby Vtheiblocl 21 helps,` offeourse, to .prevent heat.V exchange betweenYthe interior and the Y ,exterior-of: the chamberxll; but even moreVinlp'ortantlyV it'hidesrtheioot from the-patient.`Y UnderthistreatrnentV theV foot changes color1ratherlhrapid1y, assumes vra death-vlikeA gray appearance,and frequently begins to collectieV crystals;andlit vhas been. found that itfisp'sychologically Ainnivisable'.for.the patienti to have ali-opportunityVV to .seeYV lthe-footrinpthatjeondition.V Y f 'Y .Once analgesia has been establishedainlftlzle:[ilowiof` body fluids withinithefoothas been completelyhalted,

itis desirable to raise the temperature Ywithin the chain# f Y berk1'1ptoa'yaluejust'below thefreezing point fof water.k i

Usually, a' Ytemperature of V25" to 30? "F; isi found toibo optimum; andthis temperature iszmaintainedfsubstan- Y tially withoutvariation; untiljust'before lthe amputationY is performed. i v' The quick freezingeiected byrfollowingthe above procedure eliminates the'long period ofagonizing Apain from which the jpatient must `be protected, .underpreviously knownv procedures, by heavy and long-eontinued sedation. iThus the' deleterious eect of; suchl sedation Vupox1 .theV patientsgeneral condition is largely,llf not lentirely;A

' avoided. The discomfort V resulting .from `a heavyweight v.oficelvbearing upon Vthe Yinfectedli member is .completely iavoided,fs`ince .the foot is suspended,.entirelyfout off'con-"ff s tactwithlan'ythingWithinthe'chamberll'vSomefrslight l 'i movement ofthelimbwithrespect to'theicabine iSV'Pef 'i rnissiblejsoY thateven theV-slig'ht'discornfort resulting from 'thefsuspension.of-thelimbuponfthepadls isthu'sjmini; i

fdu'ces; ofrepleni'shingthe ieesupply, y.disygiosifng-.o Y Y fwaterresultinggfr'om;themeltingiofrthe.ieehand lneerungY` the bed reaona'blydry Vand 'that the Vpractice et theiprocess frgerant which is(non-toxic, lrnon-inammableand non?" 1 r 11, the patient may be keptcomfortably warm;V and' the:4

.When it is Vdesired Vto'. freeze 'a limb Vextremity;accioriingA.to'ioufr method of `procedure;fthey cabinet 10 'isfplaced il ...inaconvenientposition on adjacent-the patients bed.V Y i Now, thebarrieris raised, and the patientsV foot is placed:y

y'teriali2i 1inthe.'manner illu`strtitiijjj'YY Y Y -maintenance' offra'constantltemperaturefwithm thefre But'ef'majf @penance thence'ihntheappaj -j ratus of the present 'application completelyelirninaltes"V `he Y labor burden;inevitable'Withipreviuslyiknown ofcefv i 'Y i v if..- he

f' the; present' application fmfirviflins the feafiet' er t'r'emityinacompletely dry atmosphere, .therebygprlote l ing thepatientiagainst'thedeleteriouseiects whrchiarise possibility of*extension offireezingj V.toward Y the trunk` `yond thezpdesired region.O f. freezing, is` mininiizegh 1 Preferably, an accumlamr 45Lis,ineluded;.in in re intersting 'System anais embedded einem Y Y ingchamber is facilitated and line freezing back toward the compressor isobviated.

Preferably, the assembly 32 and the switch 28 will be so designed as tomaintain any desired temperature within the chamber 11, from ambienttemperature to 50 Fahrenheit with a variation not to exceed 2.

As designed and disclosed, the apparatus guards the patient againstdeleterious effects resulting from any failure of the refrigeratingmechanism. The cabinet is so designed that, even if the unit 29 shouldbreak down, the optimum temperature would be maintained within thechamber for a period ample to permit disconnection of the disabled unit29 and substitution ofanother equivalent unit, without any possibilityof thawing taking place in the patients foot.

Ordinarily, satisfactory analgesia and effective inhibition ofdispersion of toxins through the system can be efected by freezing onlythe distal end of the limb beyond the ankle or wrist joint. In theexeremely unusual case where it is found necessary or desirable toextend the freezing farther toward the trunk, it is entirely possible todo so with the present apparatus by opening the barrier, attaching arubber sheet in any suitable fashion -around the entryway 17, andcarrying that sheet to any desired point in the length of the patientslimb. It has been found that the mechanism is capable, when thus used,of maintaining any desired sub-freezing temperature within the entirespace enclosed by the rubber sheet.

We claim as our invention:

Apparatus for freezing a limb extremity preliminary to amputation,comprising a cabinet formed to provide a chamber, closed except for anentryway at one side,

evaporator coils outside said chamber in heat-exchange relation to thewalls of said chamber, heat-insulation means outside said chamber, meansenclosing said insulation means and said coils and cooperating with saidchamber walls to seal said insulation means hermetically from thecircumambient atmosphere, barrier means movable into and out of closingrelation with said entryway, said barrier means comprising asubstantially-rigid, substantially U-shaped frame formed to dene aninwardly-facing channel, a block of sponge rubber supported in saidchannel and spanning said frame, and means hingedly supporting the baseof said frame above said entryway, and means for establishing a flow ofrefrigerant tuid through said coils.

References Cited in the le of this patent UNITED STATES PATENTS1,222,945 Hammerstein Apr. 17, 1917 1,875,261 Pot Aug. 30, 19321,991,784 Bohemier et al. Feb. 19, 1935 2,415,455 Barnes et al. Feb. 11,1947 2,632,313 Fehr Mar. 24, 1953 FOREIGN PATENTS 910,374 France Jan.28, 1946 OTHER REFERENCES Scientific American, for April 1942, page 183.

Journal of the American Medical Association, for September 4, 1943, pp.13-17. (Copies in the Scientic Library.)

